Clarify a comment.

The previous comment was lying since collectViewVariables() doesn't really call
the buildPreliminaryFormTree() nor the buildFinalFormTree().

src/Symfony/Component/Form/Extension/DataCollector/EventListener/DataCollectorListener.php

@@ -76,8 +76,7 @@ class DataCollectorListener implements EventSubscriberInterface
             $this->dataCollector->collectSubmittedData($event->getForm());
 
             // Assemble a form tree
-            // This is done again in collectViewVariables(), but that method
-            // is not guaranteed to be called (i.e. when no view is created)
+            // This is done again after the view is built, but we need it here as the view is not always created.
             $this->dataCollector->buildPreliminaryFormTree($event->getForm());
         }
     }